Molecular recognition of fluorescent dyes with novel triethylenetetraamine-tethered bis(β-cyclodextrin) and its copper(II) complex: enhanced binding and selectivity by tether ligation

In order to explore the possibility of external modification of the binding ability through metal ligation, the inclusion complexation behavior of newly synthesized bis(β-cyclodextrin) (4) with an oligo(ethylenediamine) tether has been investigated with representative fluorescent dyes, 6-(p-toluidino)-2-naphthalenesulfonate (TNS) and 8-anilino-1-naphthalenesulfonate (ANS), and found to give enhanced binding and selectivity for the Cu(II)-ligated host (5).